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To: Robert Watson <rwatson@freebsd.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Tue, 21 Dec 2004 18:23:46 GMT."
             <Pine.NEB.3.96L.1041221182235.48875Y-100000@fledge.watson.org> 
Date: Tue, 21 Dec 2004 19:35:00 +0100
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cc: arch@freebsd.org
Subject: Re: Forcefully unmounting devfs... 
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In message <Pine.NEB.3.96L.1041221182235.48875Y-100000@fledge.watson.org>, Robe
rt Watson writes:
>
>On Sat, 18 Dec 2004, Poul-Henning Kamp wrote:
>
>> Brainteaser for the x-mas days:
>> 
>> 	What is the correct handling of busy device vnodes belonging
>> 	to a devfs mountpoint which is being forcefully unmounted ?
>> 
>> If you think this has a simple answer, please don't bother replying. 
>
>Being something of a traditionalist, I'd ask the question: what happens in
>4.x when you forceably unmount a UFS file system out from under the device
>nodes?  I'm guessing we deadfs the UFS vnodes, which results in varying
>degrees of havoc depending on the device type? 

It's worse: we specfs the vnodes which results in varying degress of success,
depending on device type.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.